A stopper attachment device with a compressed gas-propelled plunger is supplied with compressed gas, generally formed by a mixture of butane and propane, from a fuel cartridge containing, in an internal casing, gas compressed to the liquid state, referred to as "fuel" by persons skilled in the art. In addition to the fuel, the cartridge contains, between the internal casing and an external casing, a propellant formed from a mixture of nitrogen, butane and propane in the gaseous state and also intended to keep the fuel in the liquid state. A male ejection joining piece is connected to the internal casing and protrudes out of the external casing.
Upon each firing of the stopper a predetermined dose of compressed gas is injected from the fuel cartridge into a combustion chamber of the attachment device, the dose being controlled only if the compressed gas is metered in the liquid state.
In order to meter the compressed gas injected into the combustion chamber, certain attachment devices such as that disclosed in EP-0775 553A1 comprise a solenoid valve including a female joining piece for inletting compressed gas, with an integrated seal arranged in order to receive the male ejection joining piece of the fuel cartridge, the seal being intended to ensure sealing tightness of the connection between the two joining pieces. For each injection of fuel the solenoid valve is opened for a specific duration to meter fuel through, the inlet joining piece of the solenoid valve having a specific cross-section. In order to prevent possible fuel leaks, it would be appropriate to regularly change the seal which provides the sealing tightness of the solenoid valve-cartridge connection. However, changing a seal of this type has proven to be a complicated operation which, in practice, is never carried out.
It is an object of the invention to facilitate the operation of changing the seal for sealing the connection between the fuel cartridge and the solenoid valve for inletting compressed gas into the device.